1543-1607. Italian architect. Born at Melide near the Swiss-Italian border, he worked in Rome before his appointment as chief architect by Sixtus V in 1585. During the latter's five-year pontificate, Fontana's many works included the Laleian Palace and the Quirinal, and a significant contribution to the completion of the dome of St. Peter's. Dismissed for alleged misconduct be (1592), he later built the royal palace at Naples, in which city he died.